Recherche Images Maps Play YouTube Actualités Gmail Drive Plus »
Connexion
Les utilisateurs de lecteurs d'écran peuvent cliquer sur ce lien pour activer le mode d'accessibilité. Celui-ci propose les mêmes fonctionnalités principales, mais il est optimisé pour votre lecteur d'écran.

Brevets

  1. Recherche avancée dans les brevets
Numéro de publicationUS5327531 A
Type de publicationOctroi
Numéro de demandeUS 07/948,053
Date de publication5 juil. 1994
Date de dépôt21 sept. 1992
Date de priorité21 sept. 1992
État de paiement des fraisCaduc
Numéro de publication07948053, 948053, US 5327531 A, US 5327531A, US-A-5327531, US5327531 A, US5327531A
InventeursRichard Bealkowski, Dhruvkumar M. Desai, Robert B. Haig, Dennis L. Moeller, Essy Tashakori
Cessionnaire d'origineInternational Business Machines Corp.
Exporter la citationBiBTeX, EndNote, RefMan
Liens externes: USPTO, Cession USPTO, Espacenet
Data processing system including corrupt flash ROM recovery
US 5327531 A
Résumé
A personal computer is provided with primary and secondary non-volatile storage devices for initializing the system when power is turned on. The primary device is a flash RAM. A flash ROM memory controller include means to detect when the flash ROM becomes corrupted and to switch over to the secondary device for initialization allowing the flash ROM to be later reprogrammed.
Images(3)
Previous page
Next page
Revendications(9)
What is claimed is:
1. In a personal computer comprising a non-volatile primary flash read only memory (ROM) for storing initialization information including a first reset vector containing a jump instruction, said flash ROM having a predetermined first location for storing said first reset vector, a non-volatile secondary ROM for storing initialization information including a second reset vector containing a jump instruction for ranching to initialization code, said secondary ROM having a second predetermined location for storing said second reset vector, a microprocessor for reading said first location in response to a CPU reset signal, a memory controller for controlling operation of said flash ROM and said secondary ROM, and bus means interconnecting said microprocessor, said ROMs, and said memory controller, the improvement comprising:
first means in said memory controller connected to said bus means for detecting a corrupted flash ROM, when said microprocessor is reading said first location, and generating a CPU reset signal in response thereto;
second means connected to said first means for receiving said CPU reset signal therefrom and switching said second ROM to become a primary ROM; and
third means connected from said first means to said microprocessor for transmitting said CPU reset signal thereto, whereby said microprocessor is reset causing said jump instruction in said second reset vector to be fetched from said second ROM and executed to thereby branch to said initialization code and initialize said personal computer using initialization information in said second ROM.
2. A personal computer in accordance with claim 1 wherein said first means comprises a comparator having a first input for receiving a first operand read from said first location, said comparator having a second input for receiving a second predetermined operand, said comparator being operative to generate said CPU reset signal when said first operand and said second operand are different.
3. A personal computer in accordance with claim 2 wherein said second means comprises:
a selectively actuated storage device for storing a ROM select bit having first and second states, said first state selecting said flash ROM, said second state selecting said second ROM, said ROM select bit being normally set to select said flash ROM, said ROM select bit being toggled from said first state to said second state in response to said CPU reset signal.
4. A personal computer in accordance with claim 3 wherein said second means further comprises a plural bit register containing said ROM select bit and a plurality of additional bits including a write enable bit having two states for controlling enabling of the ROM selected by said ROM select bit.
5. A personal computer in accordance with claim 4 wherein said second means comprises a write enable bit generator connected to said write enable bit for generating a write enable signal and transmitting said write enable signal to said ROM selected by said ROM select bit.
6. A personal computer in accordance with claim 5 comprising:
an addressable port containing said register;
and software means executable by said microprocessor for setting said register to control operation of said flash ROM, for erasing said initialization information in said flash ROM, and for writing updated initialization information into said flash ROM including said first reset vector.
7. A personal computer in accordance with claim 6 wherein said software means is selectively operable when a power loss occurs causing corruption of said flash ROM and when said flash ROM is successfully updated by said software means.
8. A personal computer in accordance with claim 7 wherein said initialization information comprises a power on self test program, and each ROM further comprises a basic I/O system (BIOS) for accessing I/O devices.
9. A personal computer in accordance with claim 2 wherein said first and second reset vectors each contain a predetermined jump instruction having an op code, and said second operant corresponds to said op code.
Description
BACKGROUND OF THE INVENTION

This invention relates to the field of data processing, and, more particularly to improvements in recovering from a corrupt flash read only memory (ROM).

A flash ROM is a relative new storage device available for the non-volatile storage of power-on self-test (POST) and basic input/output system (BIOS) programs, and other microcode, required for system initialization. A flash ROM is an alternative to using electronically programmable read only memories (EPROM) that are used for the same purposes. A flash ROM can be reprogrammed without being removed from the system, providing a more expeditious and less costly solution over EPROMS when field updates are required. The only disadvantage to such solution is if the flash ROM becomes corrupted such as by a power loss during reprogramming, in which case there is no way to initialize the system again to reprogram the flash RAM if the system has only one initialyzing resource.

In one prior art system, both a flash ROM and an EPROM are installed in the system as primary and secondary storage resources respectively, and a hardware jumper is provided to select which resource is used to initialize the system. If the flash ROM becomes corrupted, someone (such as a systems engineer or a skilled user) must manually move the jumper to select the EPROM, power on the system and wait for it to initialize, move the jumper back to select the flash RAM, and then reprogram the flash ROM by a software utility. Although such solution works, the cost associated with it is high in terms of system down time, labor to switch the jumper, and cost of jumper itself.

SUMMARY OF THE INVENTION

One of the objects of the invention is to provide a personal computer system having primary and secondary non-volatile storage devices, including on or more flash RAMs, for storing initialization information, with improved means to recover from a flash ROM that is corrupted while being reprogrammed or updated.

Another object of the invention is to provide an automatic flash ROM recovery system for recovering from a corrupted flash RAM, which does not involve a jumper and the manual switching thereof.

A further object of the invention is to provide a flash ROM recovery system in which the system automatically determines and selects which resource is used to initialize the system when the flash ROM is by default the primary resource for initializing the system, the system automatically switching to the secondary resource if the primary flash ROM has been corrupted.

Still another object of the invention is to provide an improved flash ROM recovery system which can recover from a corrupted primary flash ROM by first initializing the system using a secondary initializing resource and then reprogramming the flash ROM without any intervention by a systems engineer of other skilled person.

Briefly, in accordance with the invention, a personal computer is provided with primary and secondary non-volatile storage devices for initializing the system when power is turned on. The primary device is a flash RAM. A flash ROM memory controller include means to detect when the flash ROM becomes corrupted and to switch over to the secondary device for initialization allowing the flash ROM the be later reprogrammed.

DRAWINGS

Other objects and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings wherein:

FIG. 1 is a block diagram of a data processing system embodying the invention;

FIG. 2 is a more detailed block diagram of a memory controller shown in FIG. 1; and

FIG. 3 is a flow chart of update and recovery operations in accordance with the invention.

DETAILED DESCRIPTION

Referring now to the drawings, and first to FIG. 1, a personal computer system 10 comprises a microprocessor 12 connected by a local bus 14 to a controller 16. Local bus 14 includes a data bus 14D, an address bus 14A, and a control bus 14C each of which has a plurality of lines for transmitting data, address, and control signals. Preferably, the microprocessor is a standard, commercially available 386sx microprocessor and local bus 14 conforms to the architecture thereof including a 24-bit address bus and a 16-bit data bus. Controller 16 comprises a bus control unit 18 and a memory control unit or controller 20. Controller 20 controls access to and operation of a main memory 22 composed of a plurality of dynamic random access memory (DRAM) devices. A data buffer 24 is connected to bus 14D and to the DRAMs. A memory bus 44 is connected between controller 20 and DRAMs 22 for transmitting the row address, column address, and control signals for accessing the main memory.

Bus control 18 provides an interface between local bus 14 and an expansion bus 38 that comprises address, data, and control busses 38A, 38D and 38C. A standard keyboard 30, floppy disk drive 32, and display 34 are also connected to bus 38 to provide I/O functions allowing user interaction with the system. A multifunction chip 28 is also connected to bus 38C and provides the functions of a direct memory access (DMA) controller, interrupt controller, time, real time clock (RTC), serial port, and parallel port. Chip 28 also includes an address buffer connected to busses 14A and 38A.

System 10 further includes a flash ROM 36 and an EPROM 40 which respectively act as the primary resource and the secondary resource for non-volatile storage of information for initializing the system when the system power is turned on. Both devices 36 and 40 are initially programmed with the same initializing information including a POST program 53, a BIOS 48, and a reset vector (RV) 54. When the system is powered on, control passes to RV 54 which is at a predetermined location in the primary resource 36. RV 54 is a jump instruction for causing control to pass to the POST program for testing and starting up the system in a standard manner. EPROM 40 is a secondary or backup resource and is used as an alternate resource in the manner described below when ROM 36 becomes corrupted. Flash ROM 36 and EPROM 40 are connected to address bus 14A to receive addresses therefrom, and to control bus 42 to receive control signals from memory controller 20, and to data bus 26. Bus 26 is in turn connected to data buffer 24.

System 10 is designed in contemplation of the possibility that the initial BIOS 48 in ROM 36 may be updated with the aid of a software utility 51 on a floppy disk 46 that also stores a new BIOS 52. Utility 51 is a program that when executed first erases flash ROM 36, and then writes the new BIOS 52 into the flash ROM. Such update process is relatively slow and takes several minutes to complete. The problem which the invention addresses and solves is the situation of the flash ROM becoming corrupted as a result a power loss during the update process. In such a situation, the old contents of the ROM have been erased and the new BIOS has not been stored therein so that subsequent system initialization cannot occur using a corrupted ROM. The solution to the problem, in accordance with the invention, is to include in memory controller 20 a recovery control (RC) 50 details of which are shown in FIG. 2 to which reference is now directed.

Recovery control 50 comprises a port 56 accessible at port address "98h" (hex) Port 56 contains an eight bit register 58 having three bits X that are unused by the invention, a reset bit "R", a write enable bit "WE", a ROM select bit "RS", and two write protect bits "WP0", "WP-1". Port 56 is connected to data bus 14D allowing information to be written into and read from register 58, by the system. During the normal operation of system 10, during system initialization, R bit is reset or "off", WE bit is off, RS bit is set on to select flash ROM 36, and WP0 and WP1 are on to write protect 36 and 40. During a BIOS update, these bits are set by utility 51 to the following states: R-off, WE-on, RS-on to select ROM 36, WP0-off to allow ROM 36 to be written into, and WP-1-on. At the successful completion of the update process, flash ROM 36 contains the new BIOS 52, POST 48, and reset vector 54. Reset vector 54 is located at address "FFFFF0h" and contains a jump instruction having an op code "EAh" in the low order byte thereof along with a "jump to" address for jumping or branching to a program that continues with initialization of the system including executing the POST program. A write enable bit generator 60 has four inputs connected to read the status of the WE, RS, WP1 and WP0 bits. The logic of generator is to generate a WE# signal only when WE is on, RS is on, WP1 is on, and WP0 is off, thereby allowing flash ROM to be reprogrammed. In order to update flash ROM 36, the software utility 51 is mounted in drive 32 and selected or activated. The utility is loaded into main memory 22 and executed causing register 58 to be loaded with the above bit settings allowing the flash ROM to be reprogrammed. Upon completion of the reprogramming, ROM 36 contains the initialization information illustrated in FIG. 2.

Controller 20 also includes means to detect a corrupted flash ROM, which means includes a comparator 62 having a first one byte input 64. Such input is preset to the value 'EAh" which corresponds to the lower order byte of RV 54. In accordance with the invention, when the system is first turned on, the microprocessor fetches or reads the instruction at ROM address "FFFFFOh" from ROM 36 into microprocesser 12 for execution. Such address is transmitted from the microprocessor along address bus 14A to an address decoder 41 that generates a chip enable bit OE# for accessing ROM 36. The instruction is transferred on bus 14D which is connected to comparator 62 so as to allow the low order byte to be compared with the preset value on input 64. If the two values are the same, the instruction is executed and processing continues in a normal manner. If the low order byte from ROM 36 is not "EAh", it indicates a corrupted ROM.

Comparator 65 has an output connected to line 65 and generates a CPU RESET signal on line 65 when the low order byte being transferred does not equal "EAh". Line 65 is connected to one input of a two input OR logic circuit 66 and to a toggle RS bit circuit 68. The second input of OR circuits 66 is connected to the R-bit of register 58. Circuit 66 has an output connected by line 67 to the CPU RESET input of microprocessor 12 whereby the microprocessor is reset either when comparator 62 generates a CPU RESET signal or when the R-bit is set on. Circuit 68 has a second input connected to read the RS-bit of register 56 and is operative to generate an output signal on line 70 for toggling RS-bit when such bit is on and a CPU reset signal is generated by comparator 62. In response to the CPU RESET signal, bit RS is saved so that on the subsequent system startup, EPROM 40 is used to initialize the system instead of flash ROM 36.

Referring to FIG. 3, when the system power is turned on in step 76, two different sequences of operation can occur dependent on whether or not the flash ROM has been corrupted. If the flash ROM is not corrupted, the CPU is reset in step 78. Step 80 then reads the reset vector 54 in ROM 36 and step 82 compares the low order byte with the value "EAh". Since the flash ROM is not corrupted, step 82 provides a positive determination and step 84 continues executing the initialization code in flash ROM 84 in the usual manner. If the flash ROM is corrupted, two passes are made. In the first pass, steps 78 and 80 occur as above, but step 82 then produces a negative determination causing step 86 to toggle the RS bit and select EPROM 40 as the ROM resource for initialization. Control then is passed along path 88 to step 78 which is reexecuted. Afterwards, step 80 reads the reset vector this time from EPROM 40 thereby causing step 82 to produce a positive result. Step 84 then continues initialization by executing initialization code in EPROM. Once EPROM 40 has initialized the system, further attempts can be made to update the flash ROM using the software utility 51, until a successful update occurs. Afterwards, ROM 36 is then set as the primary resource and the new BIOS 52' is placed in operation. It should be noted that the invention automatically allows a flash ROM to be updated, even though it has been corrupted, without requiring a skilled person to manipulate any jumper.

It should be apparent to those skilled in the art that many changes can be made in the details and arrangements of steps and parts without departing from the scope of the invention as defined in the appended claims.

Citations de brevets
Brevet cité Date de dépôt Date de publication Déposant Titre
US5163052 *12 oct. 198910 nov. 1992Ncr CorporationHigh reliability computer diagnostics system
US5239621 *26 juin 199224 août 1993Lexmark International, Inc.Printer with flash memory
US5261104 *13 nov. 19929 nov. 1993International Business MachinesFlexible computer initialization
Référencé par
Brevet citant Date de dépôt Date de publication Déposant Titre
US5428755 *11 mars 199327 juin 1995Sankyo Seiki Mfg. Co., Ltd.Method for automatically modifying program in a flash memory of a magnetic tape unit
US5522076 *28 avr. 199428 mai 1996Kabushiki Kaisha ToshibaComputer system having BIOS (basic input/output system)-ROM (Read Only Memory) writing function
US5568608 *3 mai 199522 oct. 1996E-Systems, Inc.Method for protecting data in media recording peripheral devices
US5628022 *1 juin 19946 mai 1997Hitachi, Ltd.Microcomputer with programmable ROM
US5712969 *10 sept. 199427 janv. 1998Robert Bosch GmbhMethod for completely reprogramming an erasable, non-volatile memory
US5737567 *23 oct. 19957 avr. 1998Unisys CorporationFast write initialization system for microcode RAM via data path array using pre-loaded flash memory an programmable control logic array
US5752063 *19 déc. 199512 mai 1998Packard Bell NecWrite inhibited registers
US5764995 *12 juil. 19969 juin 1998Packard Bell NecWrite once read only registers
US5793943 *29 juil. 199611 août 1998Micron Electronics, Inc.System for a primary BIOS ROM recovery in a dual BIOS ROM computer system
US5794054 *19 juil. 199611 août 1998Compaq Computer CorporationFlash ROM sharing between a processor and a controller
US5797023 *10 juil. 199718 août 1998Digital Equipment CorporationMethod and apparatus for fault tolerant BIOS addressing
US5802592 *31 mai 19961 sept. 1998International Business Machines CorporationSystem and method for protecting integrity of alterable ROM using digital signatures
US5805834 *1 août 19968 sept. 1998Zilog, Inc.For use in a computer system
US5805882 *19 juil. 19968 sept. 1998Compaq Computer CorporationComputer system and method for replacing obsolete or corrupt boot code contained within reprogrammable memory with new boot code supplied from an external source through a data port
US5815706 *20 sept. 199529 sept. 1998Dell Usa, L.P.Computer system with plug-in override of system ROM
US5835695 *31 juil. 199710 nov. 1998Micron Electronics, LlpMethod for a primary BIOS ROM recovery in a dual BIOS ROM computer system
US5860122 *12 nov. 199612 janv. 1999Matsushita Electric Industrial Co., Ltd.Backup unit including identifier conversion means
US5864698 *15 sept. 199726 janv. 1999Packard Bell NecFor enabling an initial version of a basic input output system
US5867106 *16 oct. 19952 févr. 1999Packard Bell NecComputer system
US5870520 *13 mars 19969 févr. 1999Packard Bell NecFlash disaster recovery ROM and utility to reprogram multiple ROMS
US5933846 *2 nov. 19953 août 1999Nec CorporationRewritable ROM file device having read/write buffer access control via copy of rewritable area
US5938764 *23 oct. 199617 août 1999Micron Electronics, Inc.Apparatus for improved storage of computer system configuration information
US5938774 *30 sept. 199717 août 1999Winbond Electronics Corp.Apparatus for repairing faulty program segments in embedded microprocessor systems
US5940627 *13 mars 199717 août 1999Compaq Computer CorporationUser selectable feature set for a flash ROM based peripheral
US5974558 *16 oct. 199526 oct. 1999Packard Bell NecResume on pen contact
US5990875 *16 oct. 199523 nov. 1999Packard Bell NecDouble pen up event
US5996082 *16 oct. 199530 nov. 1999Packard Bell NecSystem and method for delaying a wake-up signal
US6005533 *16 oct. 199521 déc. 1999Packard Bell NecRemote occlusion region
US6018806 *16 oct. 199525 janv. 2000Packard Bell NecMethod and system for rebooting a computer having corrupted memory using an external jumper
US6023758 *22 mai 19968 févr. 2000Matsushita Electric Industrial Co., Ltd.Method and processor for changing program by replacing instruction stored in ROM with predetermined value to be interpreted as an instruction
US6092117 *16 oct. 199518 juil. 2000Packard Bell NecSystem and method for automatically reconnecting a wireless interface device to a host computer
US6092164 *23 juil. 199718 juil. 2000Mitsubishi Denki Kabushiki KaishaMicrocomputer having division of timing signals to initialize flash memory
US6092190 *30 janv. 199718 juil. 2000Neopost LimitedElectronic apparatus including a memory device and method of reprogramming the memory device
US6108727 *15 janv. 199722 août 2000Packard Bell NecSystem having wireless interface device for storing compressed predetermined program files received from a remote host and communicating with the remote host via wireless link
US6126327 *16 oct. 19953 oct. 2000Packard Bell NecRadio flash update
US6148344 *16 oct. 199514 nov. 2000Nec CorporationSystem and method for enabling an IPX driver to accommodate multiple LAN adapters
US6154838 *5 oct. 199828 nov. 2000Le; Hung Q.Flash ROM sharing between processor and microcontroller during booting and handling warm-booting events
US6157979 *14 mars 19985 déc. 2000Advanced Technology Materials, Inc.Programmable controlling device with non-volatile ferroelectric state-machines for restarting processor when power is restored with execution states retained in said non-volatile state-machines on power down
US6167344 *15 mars 199726 déc. 2000Robert Bosch GmbhProcess for operating a controller with a programmable memory
US6182187 *7 avr. 199330 janv. 2001Compaq Computer CorporationSystem ROM including a flash EPROM and a ROM for storing primary boot code replacing a block flash EPROM
US618569627 mai 19986 févr. 2001Micron Electronics, Inc.System for a primary BIOS ROM recovery in a dual BIOS ROM computer system
US620903416 oct. 199527 mars 2001Nec CorporationRemote keyboard macros activated by hot icons
US6233681 *24 nov. 199815 mai 2001Samsung Electronics Co. Ltd.Computer system and a control method of the same for in-system reprogramming of a fixed flash ROM when access to the fixed flash ROM is not possible
US624051930 avr. 199829 mai 2001Compaq Computer CorporationComputer method and apparatus to prompt for administrative password to flash a corrupted non-volatile memory
US625328115 juin 199826 juin 2001U.S. Philips CorporationMethod for updating firmware of a computer peripheral device
US626271923 oct. 199717 juil. 2001Packard Bell Nec, Inc.Mouse emulation with a passive pen
US6272628 *14 déc. 19987 août 2001International Business Machines CorporationBoot code verification and recovery
US6272630 *14 déc. 19997 août 2001Winbond Electronics CorporationMethod and device for reserving wake-up functions of computer system after power loss
US627915315 janv. 199721 août 2001Nec CorporationMulti-user flash ROM update
US628264030 oct. 199728 août 2001Micron Technology, Inc.Method for improved storage of computer system configuration information
US632765323 nov. 19984 déc. 2001Samsung Electronics Co., Ltd.Technique for easily changing operating systems of a digital computer system using at least two pushbuttons
US636349230 avr. 199826 mars 2002Compaq Computer CorporationComputer method and apparatus to force boot block recovery
US6374318 *16 oct. 199816 avr. 2002Dell Usa, L.P.Filter-circuit for computer system bus
US6430738 *1 juil. 19936 août 2002International Business Machines CorporationMethod and system for reversible installation of software applications in a data processing system utilizing an automated archival process
US64346976 oct. 199913 août 2002Micron Technology, Inc.Apparatus for savings system configuration information to shorten computer system initialization time
US643868717 août 200120 août 2002Micron Technology, Inc.Method and apparatus for improved storage of computer system configuration information
US6442623 *21 déc. 199827 août 2002Samsung Electronics Co., Ltd.Method and arrangement for restoring a damaged ROM BIOS using a previously compressed ROM BIOS image
US6449735 *1 juil. 199610 sept. 2002Intel CorporationMethod and apparatus for providing improved diagnostic functions in a computer system
US6467045 *1 juin 200115 oct. 2002Hitachi, Ltd.Recovery support method for recovering from failure of an external storage device
US65196986 oct. 199911 févr. 2003Micron Technology, Inc.Method for saving system configuration information to shorten computer system initialization time by checking the state of a chassis intrusion detection circuit
US6571347 *24 mai 199927 mai 2003Winbond Electronics CorporationApparatus and method for intelligent computer initiation program recovery
US6604194 *18 nov. 19995 août 2003Lg Electronics Inc.Program updating method and apparatus for communication terminal system
US6625727 *23 nov. 199923 sept. 2003Motorola, Inc.Apparatus and method for configuring a data processing system by retrieving a configuration value from storage device using reset vector and configuring parameters after reset
US666498215 janv. 199716 déc. 2003Nec CorporationMulti-user on-screen keyboard
US668360516 oct. 199527 janv. 2004Nec CorporationScreen saver disabler
US6704865 *23 déc. 19999 mars 2004Delphi Technologies, Inc.Microprocessor conditional deterministic reset vector method
US6745329 *22 sept. 19991 juin 2004Micro-Star International Co., Ltd.Method for preventing a BIOS to get viruses
US6757838 *13 oct. 200029 juin 2004Hewlett-Packard Development Company, L.P.Hardware independent implementation of computer system BIOS recovery
US676001716 oct. 19956 juil. 2004Nec CorporationWireless interface device for communicating with a remote host computer
US6785846 *22 déc. 200031 août 2004Intel CorporationInexpensive method for diagnosing manufacturing defects in an embedded system
US6795940 *18 sept. 200121 sept. 2004Nissan Motor Co., Ltd.Method of and apparatus for executing diagnostic testing of a ROM
US6854055 *16 oct. 20008 févr. 2005Endress + Hauser Flowtec AgMethod and system for switching active configuration memory during on-line operation of programmable field mounted device
US6877063 *22 déc. 20005 avr. 2005Xilinx, Inc.Multiple memory aliasing for a configurable system-on-chip
US6892323 *12 mars 200210 mai 2005Giga-Byte Technology Co., Ltd.Dual basic input/output system for a computer
US696378315 janv. 19978 nov. 2005Packard Bell NecAudio compression in a wireless remote interface tablet
US697358629 avr. 20026 déc. 2005International Business Machines CorporationSystem and method for automatic dynamic address switching
US7010679 *15 juil. 20027 mars 2006Mitac Technology Corp.System for selecting from multiple BIOS versions stored in a single memory device
US708595629 avr. 20021 août 2006International Business Machines CorporationSystem and method for concurrent logical device swapping
US712043312 mars 200410 oct. 2006Nec CorporationMultiple wireless remote interfaces to a single server
US72493791 févr. 200224 juil. 2007Systems Advisory Group Enterprises, Inc.Method and apparatus for implementing process-based security in a computer system
US729934822 déc. 200420 nov. 2007Endress + Hauser Flowtec AgProgrammable field mounted device
US7349476 *28 mars 200525 mars 2008Matsushita Electric Industrial Co., Ltd.Digital motion picture decoding apparatus and digital motion picture decoding method
US741215422 mars 200412 août 2008Matsushita Electric Industrial Co., Ltd.Digital motion picture decoding apparatus and digital motion picture decoding method
US7653935 *21 avr. 200526 janv. 2010Hitachi, Ltd.File server for translating user identifier
US7761671 *14 août 200720 juil. 2010Zi San Electronics Corp.Data displacement bypass system
US782300717 févr. 200626 oct. 2010International Business Machines CorporationApparatus, system, and method for switching a volume address association in a point-in-time copy relationship
US7844811 *23 août 200730 nov. 2010Micron Technology, Inc.Using chip select to specify boot memory
US8151104 *27 juin 20083 avr. 2012Lenovo (Singapore) Pte. Ltd.Establishing user-defined management engine default settings stored in a system memory
US837091025 janv. 20105 févr. 2013Hitachi, Ltd.File server for translating user identifier
US838684227 avr. 201026 févr. 2013Asustek Computer Inc.Computer system with damaged bios data recovering function and recovering method thereof
US8407684 *30 nov. 200626 mars 2013Samsung Electronics Co., Ltd.Memory card and method of updating memory card program
US867710922 nov. 201018 mars 2014Micron Technology, Inc.Non-volatile memory device adapted to identify itself as a boot memory
CN101908008B3 juin 200926 sept. 2012大唐移动通信设备有限公司Device and method for switching BIOS (Basic Input/Output System)
EP0788115A2 *29 janv. 19976 août 1997Neopost LimitedElectronic apparatus including a memory device and method of reprogramming the memory device
EP0917054A2 *6 nov. 199819 mai 1999Digital Equipment CorporationMemory paging method for microcontrollers
EP1008042A1 *6 août 199714 juin 2000Macronix International Co., Ltd.Fault-tolerant architecture for in-circuit programming
EP1744244A26 août 199717 janv. 2007Macronix International Co., Ltd.Fault-tolerant architecture for in-circuit programming
EP2254051A1 *28 avr. 201024 nov. 2010ASUSTeK Computer Inc.Computer system with damaged bios data recovering function and recovering method thereof
Classifications
Classification aux États-Unis714/6.1, 714/E11.133, 713/1
Classification internationaleG06F11/14, G06F9/445, G11C29/00
Classification coopérativeG11C29/74, G06F8/66, G06F11/1417
Classification européenneG11C29/74, G06F8/66, G06F11/14A8B
Événements juridiques
DateCodeÉvénementDescription
4 août 2005ASAssignment
Owner name: LENOVO (SINGAPORE) PTE LTD., SINGAPORE
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:INTERNATIONAL BUSINESS MACHINES CORPORATION;REEL/FRAME:016891/0507
Effective date: 20050520
Owner name: LENOVO (SINGAPORE) PTE LTD.,SINGAPORE
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:INTERNATIONAL BUSINESS MACHINES CORPORATION;REEL/FRAME:16891/507
3 sept. 2002FPExpired due to failure to pay maintenance fee
Effective date: 20020705
5 juil. 2002LAPSLapse for failure to pay maintenance fees
30 janv. 2002REMIMaintenance fee reminder mailed
12 nov. 1997FPAYFee payment
Year of fee payment: 4
12 nov. 1992ASAssignment
Owner name: INTERNATIONAL BUSINESS MACHINES CORP., NEW YORK
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:BEALKOWSKI, RICHARD;DESAI, DHRUVKUMAR M.;HAIG, ROBERT B.;AND OTHERS;REEL/FRAME:006415/0953
Effective date: 19921106